1. Field of the Invention
The present invention relates to a paper-discharging tray used in an image-forming apparatus such as a laser printer or an electrostatic photographic copying machine.
2. Description of the Prior Art
FIG. 5 shows a portion of a conventional laser printer in the vicinity of a paper-discharging portion. Referring to FIG. 5, reference numeral 61 designates a fixing device provided with a heating roll 62 and a pressing roll 63 arranged therewithin so as to contact one another. Reference numeral 64 designates a paper-discharging device which is arranged on the downstream side of the fixing device 61 and comprises upper and lower rolls 65, 66 arranged so as to contact one another. And, reference numeral 67 designates a paper-discharging tray which is arranged on the downstream side of the paper-discharging device 64 and has an upper surface 68 formed so straight (or linear) as seen in side view and an idle (or free) end portion 69. The paper-discharging tray 64 is mounted on a side plate 71 of a body of the laser printer in such a manner that the tray is inclined such that the idle end portion 69 is slightly above a base end portion 70.
With this construction, a paper 72 conveyed from a transfer device (not shown) is subjected to an appointed fixing treatment as it passes between the rolls 62, 63 of the fixing device 61 and then passes between the rolls 65, 66 of the paper-discharging device 64 to be discharged onto the paper-discharging tray 67 with an image-forming surface facing upwardly.
However, in the laser printer, slightly thick papers, such as post cards and envelopes, may be used as the paper 72 on which an image is to be formed, in addition to the usual copying paper (referred to as usual paper) when papers are doubled (or tripled), such as with envelopes, the upper paper and lower paper will undergo different degrees of heat-shrinkage when they pass between the rolls 62, 63 of the fixing device 61. Thus, the paper 72 is liable to be curled along the upper heating roll 62 such that the paper 72 received on the paper-discharging tray 67, which has passed through the paper-discharging device 64, will be curled toward the image-forming surface 73 side, as shown in FIG. 5. Because the above-described conventional paper-discharging tray 67 has a form corresponding to the shape of the usual paper, the problem may arise that, for example, the discharged papers 72 become misshaped during the storage or may fall out of the paper-discharging tray 67.
In addition, in the laser printer or the like, when the paper, which has passed through the fixing device and the paper-discharging device, is disposed with its image-forming surface turned downward, (i.e. the so-called face down condition), the paper-discharging tray is arranged above the body of the laser printer (although this is not shown) and the paper-discharging tray is disposed at a considerable incline (of for example about 40.degree.).
Because, when the paper-discharging tray is substantial-ly horizontal, it is necessary in order to maintain an appointed storage capacity to arrange the paper-discharging device at a position above the paper-discharging tray. This arrangement, however, disadvantageously results in an increase in the overall size of the laser printer.
However, when the paper-discharging tray is positioned at an incline, a leading end of unusually flexible paper may not be properly raised to the end of the sharply inclined paper-discharging tray, thereby causing the stocking capacity of the paper in the tray to be reduced.